I mean, it is years of work, speaking from experience. I make a similar tool (but for Node.js/Vue, if you're not a fan of Django), and it took around two years

I mean, it is years of work, speaking from experience. I make a similar tool (but for Node.js/Vue, if you're not a fan of Django), and it took around two years to get it to where it is, with user account creation/management, subscriptions, teams, admin dashboard, scripting, etc. I'm definitely not charging as much as Bullet Train, but also I feel fully justified in charging instead of open sourcing it. It's been my sole serious side-project for years now after all. The problem for trials of stuff like this, is that you have no real way of enforcing it. You just have to hope that trialers feel like doing the right thing and paying if they continue to use it, because trying to recover a few hundred dollars through legal means is just not worth the time and money you'd have to spend. In the end, I settled on a 60-day money-back guarantee, and I've already issued a few already, to folks who thought it had a feature it didn't yet, or ended up not pursuing their idea, etc, so it seems to work pretty well.